Battery module

Abstract

The present invention discloses a battery module. The battery module of the present invention comprises: a plurality of inner busbars disposed on a busbar frame, each having a first electrode lead and a second electrode lead connected thereto; a first terminal busbar disposed on the busbar frame and having a first electrode lead connected thereto; a second terminal busbar disposed on the busbar frame and having a second electrode lead connected thereto having a polarity opposite to that of the first electrode lead; a circuit board having a plurality of substrate joints formed thereon; a plurality of wire portions soldered to the first electrode lead and the substrate joints; and a joining member joined to the second terminal busbar and having the wire portions soldered thereto.

Description

Technology Field

[0001] The present invention relates to a battery module capable of automating the manufacturing of the battery module, inspecting bonding defects along with the bonding process, enabling soldering rework, reducing bonding components, and simplifying the bonding process. Background Technology

[0002] Generally, secondary batteries consist of a positive electrode, a negative electrode, and an electrolyte, and generate electrical energy through chemical reactions. The use of secondary batteries is gradually increasing due to their advantage of being rechargeable and dischargeable. Among these secondary batteries, lithium-ion batteries are widely used as power sources for electronic communication devices or as driving forces for high-output hybrid and electric vehicles, as they possess a high energy density per unit weight.

[0003] In terms of battery shape, there is increasing demand for prismatic and pouch-type batteries, which can be applied to products such as mobile phones due to their thin profiles. Regarding battery materials, there is growing demand for lithium-ion batteries, such as lithium-ion polymer batteries, which offer high energy density, discharge voltage, and output stability.

[0004] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. The operating voltage of these battery cells is approximately 2.5V to 4.2V. If a higher output voltage is required, a battery module is formed by connecting multiple battery cells in series. A battery pack is formed by connecting the aforementioned multiple battery modules, and a battery pack is formed by connecting multiple battery cells in parallel according to the charge / discharge capacity required for the battery pack. Accordingly, the number of battery cells and the electrical connection structure of the battery pack can be varied depending on the required output voltage or charge / discharge capacity.

[0005] The battery module includes an interconnect board (ICB). The interconnect board connects each battery cell in series in the high-voltage battery module.

[0006] The interconnect board includes a flexible substrate. Multiple sensing plates are connected to the flexible substrate and welded to each busbar, and multiple battery cells are connected to each of the multiple busbars. In this case, multiple sensing plates are first welded to the flexible substrate, the multiple sensing plates are welded to the busbars, and the electrode leads of the battery cells are welded to the busbars. This interconnect board provides a serial connection structure capable of measuring the voltage of the battery cells.

[0007] The battery module described above is laser-welded between a flexible substrate and a sensing plate, and between a sensing plate and a busbar. During laser welding, there must be no gap between the two metal components to ensure welding strength. Due to the flexible nature of the flexible substrate, it was difficult for the clamping device to fix the position of the flexible substrate and the sensing plate. Consequently, it was difficult to automate the clamping operation, so a worker had to perform the clamping operation manually.

[0008] In addition, when the sensing plate is laser welded to the busbar, the surface area of ​​the sensing plate is significantly narrower than that of the weld bead. Consequently, in the event of a welding defect, the unwelded portion of the sensing plate becomes too small, making it difficult to re-weld the sensing plate to the busbar.

[0009] In addition, even if the area of ​​the sensing plate was increased, it was more difficult to re-weld the sensing plate and the busbar because the sensing plate underwent chemical or thermal deformation due to the high temperature heat during laser welding.

[0010] Furthermore, since the aforementioned laser welding joins metal components by heating and melting them using a laser, the strength of the laser weld had to be evaluated through destructive testing, which involves cutting the weld to inspect it. Consequently, it was difficult to perform a comprehensive strength evaluation of the welds. Additionally, the time required for the strength evaluation of the welds increased.

[0011] In addition, a sensing plate is connected to the flexible substrate to bond it to the busbar. Consequently, material costs increase proportionally to the number of sensing plates connected, and the bonding time between the flexible substrate and the busbar may be additionally extended by the time required to weld the sensing plate to the flexible substrate. Furthermore, the assembly time and cost of the battery module may increase.

[0012] The background technology of the present invention is disclosed in Korean Published Patent Application No. 2019-0027096 (published on March 14, 2019, title of invention: Battery cell module equipped with a protective structure for a flexible circuit board). The problem to be solved

[0013] The present invention was devised to solve the aforementioned problems and aims to provide a battery module that does not require welding a sensing plate to a circuit board.

[0014] The present invention aims to provide a battery module that can reduce the number of assembly steps and shorten the assembly time.

[0015] The present invention aims to provide a battery module capable of automating the soldering process of a circuit board and a wire portion by omitting the clamping process.

[0016] The present invention aims to provide a battery module capable of re-soldering a wire portion in an unsoldered part of a joint member in the event of a soldering defect.

[0017] The present invention aims to provide a battery module capable of performing a bonding strength test of the wire portion during the soldering process of the wire portion and re-soldering the wire portion.

[0018] The present invention aims to provide a battery module capable of sufficiently securing soldering strength when the wire portion is soldered to the electrode lead and the circuit board.

[0019] The technical problems of the present invention are not limited to the purposes mentioned above, and other unmentioned purposes and advantages of the present invention may be understood from the following description and will be more clearly understood by the embodiments of the present invention. Furthermore, it will be readily apparent that the purposes and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims. means of solving the problem

[0020] To solve the above-mentioned problem, a battery module according to the present invention comprises: a plurality of inner busbars disposed on a busbar frame, each having a first electrode lead and a second electrode lead connected thereto; a first terminal busbar disposed on the busbar frame and having a first electrode lead connected thereto; a second terminal busbar disposed on the busbar frame and having a second electrode lead connected thereto having a polarity opposite to that of the first electrode lead; a circuit board having a plurality of substrate joints formed thereon; a plurality of wire portions soldered to the first electrode lead and the substrate joints; and a bonding member bonded to the second terminal busbar and having the wire portions soldered thereto.

[0021] The above joining member may be formed of the same material as the wire part.

[0022] The above joining member and the above wire part may include aluminum.

[0023] The above-mentioned joining member and the above-mentioned wire portion can be joined by melting soldering paste.

[0024] The first electrode lead can be formed of the same material as the wire part.

[0025] The inner busbar, the first electrode lead, and the second electrode lead can be joined by melting them with a laser.

[0026] The second electrode lead can be formed of the same material as the inner busbar.

[0027] The first terminal busbar and the second terminal busbar can be positioned on the outer periphery of a plurality of inner busbars.

[0028] The above-mentioned joining member can be laminated to the second terminal busbar and joined by melting it with a laser to the second terminal busbar.

[0029] The above joining member can be formed in a plate shape.

[0030] The second terminal busbar includes an extension extending from the side of the second terminal busbar, and the joining member can be joined to the extension.

[0031] The above extension may be formed of the same material as the second terminal busbar.

[0032] The above-mentioned joining member and the above-mentioned extension can be joined by melting with a laser.

[0033] The above joining member is formed of the same material as the wire part and can be welded to the side of the second terminal busbar.

[0034] The above-mentioned joining member and the second terminal busbar can be welded by friction stir welding.

[0035] The above wire portion may include: a wire body portion shaped to be bent toward the substrate joint portion and the inner busbar; a first wire joint portion formed curvedly on one side of the wire body portion and soldered to the substrate joint portion; and a second wire joint portion formed curvedly on the other side of the wire body portion and soldered to the first electrode lead or the joint member.

[0036] The first wire joint above may be formed convexly toward the substrate joint.

[0037] The second wire joint may be formed convexly toward the first electrode lead or the joint member.

[0038] The first joint and the second joint may be formed in a rounded shape. Effects of the invention

[0039] According to the present invention, since the wire portion is soldered to the circuit board, the first electrode lead, and the bonding member, there is no need to weld the sensing plate to the circuit board. Accordingly, the welding process for connecting the sensing plate to the circuit board can be omitted.

[0040] According to the present invention, since a sensing plate can be omitted from the circuit board, the number of parts of the battery module can be reduced, and the assembly time and assembly labor of the battery module can be reduced.

[0041] According to the present invention, since the sensing plate can be omitted from the circuit board, it is not necessary to perform a clamping process to fix the positions of the flexible circuit board and the sensing plate.

[0042] According to the present invention, since the clamping operation can be omitted, the process of soldering the circuit board and the wire portion can be automated.

[0043] According to the present invention, a wire portion with a small diameter is soldered to a bonding member with a large surface area. Accordingly, if a soldering defect occurs when the wire portion is soldered to the circuit board and the bonding member, the wire portion can be resoldered to the unsoldered portion of the bonding member.

[0044] According to the present invention, since the wire portion is soldered at a significantly lower temperature compared to laser welding, chemical or thermal deformation of the first electrode lead, circuit board, and bonding member may hardly occur. Accordingly, in the event of a soldering defect in the wire portion, the wire portion can be resoldered to the first electrode lead, the substrate bonding portion of the circuit board, and the bonding member.

[0045] According to the present invention, after the wire portion is soldered, a tension clamp pulls the wire portion to test the bonding strength of the soldered portion. Accordingly, the bonding strength of the soldered portion can be evaluated through non-destructive testing.

[0046] According to the present invention, since the bonding strength of the soldering portion can be evaluated simultaneously during the soldering process of the wire portion, the time required for evaluating the strength of the soldering portion can be significantly reduced. In addition, if a soldering defect occurs in the wire portion, the wire portion can be resoldered quickly. Furthermore, the strength of the soldering portion can be evaluated in real time, and the strength of the soldering portion can be inspected for all members.

[0047] According to the present invention, since the bonding member is connected or bonded to the wire portion and the second electrode lead of a different material, sufficient soldering strength can be secured even when the wire portion is soldered to the second electrode lead and the circuit board.

[0048] In addition to the effects described above, the specific effects of the present invention are described together with the specific details for implementing the invention below. Brief explanation of the drawing

[0049] FIG. 1 is a schematic perspective view illustrating a battery pack according to the present invention. FIG. 2 is a schematic perspective view illustrating the battery module of FIG. 1. FIG. 3 is a schematic perspective view illustrating an inner busbar, a first terminal busbar, a second terminal busbar, and a wire section installed on the front busbar frame of the battery module of FIG. 2. FIG. 4 is an exploded perspective view schematically illustrating the inner busbar, the first terminal busbar, and the second terminal busbar installed on the front side busbar frame of FIG. 3. FIG. 5 is an enlarged view schematically illustrating the state in which the wire portion of the front side busbar frame of FIG. 3 is soldered to the first electrode lead of the inner busbar and the circuit board. FIG. 6 is an enlarged view schematically illustrating the state in which the wire portion of the front side busbar frame of FIG. 3 is soldered to the connecting member of the second terminal busbar and the circuit board. FIG. 7 is a schematic side view illustrating a state in which soldering is easily performed even if a height difference occurs in the wire portion of the front busbar frame of FIG. 3. FIG. 8 is a schematic plan view illustrating the inner busbar, the first terminal busbar, and the second terminal busbar installed on the front side busbar frame of FIG. 3. FIG. 9 is a schematic plan view illustrating the inner busbar and wire section installed on the rear busbar frame of FIG. 2. FIG. 10 is a schematic perspective view illustrating an inner busbar, a first terminal busbar, a second terminal busbar, and a wire section installed on a front busbar frame of a battery module according to a second embodiment of the present invention. FIG. 11 is an exploded perspective view schematically illustrating an inner busbar, a first terminal busbar, a second terminal busbar, and a wire section installed on the front side busbar frame of FIG. 10. FIG. 12 is an enlarged view schematically illustrating the state in which the wire portion of the front busbar frame of FIG. 10 is soldered to the first electrode lead of the inner busbar and the circuit board. FIG. 13 is an enlarged view schematically illustrating the state in which the wire portion of the front side busbar frame of FIG. 10 is soldered to the connecting member of the second terminal busbar and the circuit board. FIG. 14 is a schematic plan view illustrating an inner busbar, a first terminal busbar, and a second terminal busbar installed on the front side busbar frame of FIG. 10. FIG. 15 is a schematic perspective view illustrating an inner busbar, a first terminal busbar, a second terminal busbar, and a wire section installed on a front busbar frame of a battery module according to a third embodiment of the present invention. FIG. 16 is an exploded perspective view schematically illustrating the inner busbar, first terminal busbar, second terminal busbar, and wire section installed on the front side busbar frame of FIG. 15. FIG. 17 is an enlarged view schematically illustrating the state in which the wire portion of the front side busbar frame of FIG. 15 is soldered to the first electrode lead of the inner busbar and the circuit board. FIG. 18 is an enlarged view schematically illustrating the state in which the wire portion of the front side busbar frame of FIG. 15 is soldered to the connecting member of the second terminal busbar and the circuit board. FIG. 19 is a perspective view schematically illustrating the structure of the second terminal busbar and the connecting member in the front side busbar frame of FIG. 15. FIG. 20 is a schematic plan view illustrating an inner busbar, a first terminal busbar, and a second terminal busbar installed on the front side busbar frame of FIG. 15. FIG. 21 is a schematic perspective view illustrating the state in which the second terminal busbar and the joining member are friction stir welded in the front side busbar frame of FIG. 15. Specific details for implementing the invention

[0050] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0051] The present invention is not limited to the embodiments disclosed below, but can be modified and implemented in various different forms. The embodiments provided are merely intended to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. Accordingly, the present invention should be understood not to be limited to the embodiments disclosed below, but to include all modifications, equivalents, and substitutions that fall within the technical spirit and scope of the present invention, as well as substituting or adding the configuration of any one embodiment with the configuration of another embodiment.

[0052] The attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and the technical concept disclosed in this specification is not limited by the attached drawings; rather, it should be understood that they include all modifications, equivalents, and substitutions that fall within the spirit and technical scope of the invention. In the drawings, components may be depicted as being exaggeratedly large or small in size or thickness for the sake of convenience of understanding, but the scope of protection of the invention should not be interpreted restrictively as a result thereof.

[0053] The terms used in this specification are used merely to describe specific embodiments or examples and are not intended to limit the invention. Furthermore, singular expressions include plural expressions unless the context clearly indicates otherwise. Terms such as "includes" or "consists of" in this specification are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in this specification. That is, terms such as "includes" or "consists of" in this specification should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0054] Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0055] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0056] When it is stated that one component is "above" or "below" another component, it should be understood that it is not only placed directly above the other component, but that another component may also exist in between.

[0057] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0058] Hereinafter, a battery module according to the first embodiment of the present invention will be described.

[0059] FIG. 1 is a perspective view schematically illustrating a battery pack according to the present invention, FIG. 2 is a perspective view schematically illustrating a battery module of FIG. 1, FIG. 3 is a perspective view schematically illustrating an inner busbar, a first terminal busbar, a second terminal busbar, and a wire section installed on a front busbar frame of the battery module of FIG. 2, FIG. 4 is an exploded perspective view schematically illustrating an inner busbar, a first terminal busbar, and a second terminal busbar installed on a front busbar frame of FIG. 3.

[0060] Referring to FIGS. 1 to 4, a battery module (100) according to the first embodiment of the present invention includes a plurality of inner busbars (130), a first terminal busbar (140), a second terminal busbar (150), a circuit board (160), a plurality of wire sections (170), and a joining member (180).

[0061] A plurality of battery modules (100) are arranged inside the battery pack (10). The plurality of battery modules (100) may be arranged in a single row or in multiple columns.

[0062] The battery module (100) includes a module frame (101) that forms the exterior. A plurality of battery cells (not shown) are stacked inside the module frame (101). End plates (103F, 103R) are respectively disposed on the front and rear sides of the module frame (101). Busbar frames (110F, 110R) are respectively disposed between the end plates (103F, 103R) and the battery cells. The end plates (103F, 103R) and the busbar frames (110F, 110R) can be formed in the shape of a square panel overall. A portion of the first terminal busbar (140) and the second terminal busbar (150) may be exposed on the periphery of the front busbar frame (110F) and the front end plate (103F).

[0063] In the busbar frame (110F, 110R), inner ribs (111) are formed protrudingly to restrain both sides in the width direction of the inner busbar (130). Two inner ribs (111) are installed for each inner busbar (130). The inner ribs (111) can be formed in a straight line. In the busbar frame (110F, 110R), outer ribs (112) are formed protrudingly to restrain both sides in the width direction of the first terminal busbar (140) and the second terminal busbar (150). These inner ribs (111) and outer ribs (112) can be formed in various shapes as long as they restrain the inner busbar (130) and the terminal busbars (140, 150).

[0064] In the busbar frames (110F, 110R), slit portions (113) are formed to allow electrode leads (121, 122) connected to battery cells (not shown) to pass through. The slit portions (113) are formed on both sides of the inner rib (111) and on one side of the outer rib (112). The slit portions (113) may be formed parallel to the inner rib (111) and the outer rib (112). The electrode leads (121, 122) passing through the slit portions (113) on both sides of the inner rib (111) are welded to the inner busbar (130). The electrode leads (121, 122) passing through the slit portion (113) on one side of the outer rib (112) are welded to the first terminal busbar (140) and the second terminal busbar (150).

[0065] The busbar frame (110F, 110R) is provided with partition ribs (114) to restrain the longitudinal sides of the inner busbar (130) and the terminal busbar (140, 150). The upper partition ribs (114) divide the area where the inner busbar (130) and the terminal busbar (140, 150) are installed and the area where the circuit board (160) is installed. The partition ribs (114) can be positioned perpendicularly to the inner rib (111) and the outer rib (112). These partition ribs (114) can be formed in a slender, long plate shape. On the front busbar frame (110F), through holes (115) are formed on the longitudinal sides of the upper partition ribs (114) to allow the first terminal busbar (140) and the second terminal busbar (150) to pass through. The first terminal busbar (140) and the second terminal busbar (150) are installed so as to be exposed to the outside after passing through the through-hole section (115). The through-hole section (115) is not formed in the upper section rib (114) of the rear side busbar frame (110R).

[0066] A mounting rib (116) is formed on the busbar frame (110F, 110R) to support the circuit board (160). At least two mounting ribs (116) are formed side by side so that the circuit board (160) is stably supported. The mounting ribs (116) are formed shorter than the length of the circuit board (160).

[0067] The busbar frame (110F, 110R) includes a plurality of fixing pins (117) protruding from both sides in the longitudinal direction of the mounting rib (116). Two or more fixing pins (117) may be installed on each side of the mounting rib (116). Fixing holes (161) are formed on both sides in the longitudinal direction of the circuit board (160) so that the fixing pins (117) can be inserted.

[0068] The first electrode lead (121) and the second electrode lead (122) have opposite polarities. Additionally, the first electrode lead (121) and the second electrode lead (122) are formed from different materials. For example, the first electrode lead (121) may be formed from aluminum or an aluminum alloy, and the second electrode lead (122) may be formed from copper or a copper alloy.

[0069] A plurality of inner busbars (130) are arranged on busbar frames (110F, 110R), and a first electrode lead (121) and a second electrode lead (122) are connected to each. The inner busbars (130) are seated between the inner ribs (111). An elongated hole (not shown) is formed along the longitudinal direction of the inner busbar (130) in the center of the inner busbar (130). A first electrode lead (121) and a second electrode lead (122) are connected to each inner busbar (130). These inner busbars (130) may be formed partly or entirely of copper material.

[0070] The first terminal busbar (140) is positioned on the front busbar frame (110F) and connected to the first electrode lead (121). The first terminal busbar (140) is a part connected to an external terminal (not shown). The first terminal busbar (140) is positioned on the outermost sides of a plurality of inner busbars (130). One side of the first terminal busbar (140) has a first bending portion (141) formed by being bent vertically, and a first fastening hole portion (not shown) is formed in the first bending portion (141) to be connected to an external terminal. This first terminal busbar (140) may be formed in part or in whole from copper material.

[0071] A second terminal busbar (150) is positioned on a front busbar frame (110F), and a second electrode lead (122) having opposite polarity to a first electrode lead (121) is connected to each. The second terminal busbar (150) is connected to an external terminal (not shown) with opposite polarity to an external terminal (not shown) connected to the first terminal busbar (140). The second terminal busbar (150) is positioned at the outermost edge of a plurality of inner busbars (130). The second terminal busbar (150) is positioned on the opposite side of the first terminal busbar (140). A second bending portion (151) is formed on one side of the second terminal busbar (150) and is vertically bent, and a second fastening hole portion (not shown) is formed in the second bending portion (151) to be connected to an external terminal. These second terminal busbars (150) may be formed in part or in whole from copper.

[0072] FIG. 5 is an enlarged view schematically illustrating the state in which the wire portion of the front busbar frame of FIG. 3 is soldered to the first electrode lead of the inner busbar and the circuit board; FIG. 6 is an enlarged view schematically illustrating the state in which the wire portion of the front busbar frame of FIG. 3 is soldered to the joining member of the second terminal busbar and the circuit board; FIG. 7 is a side view schematically illustrating the state in which the wire portion is easily soldered even if a height difference occurs in the front busbar frame of FIG. 3; FIG. 8 is a plan view schematically illustrating the inner busbar, the first terminal busbar, and the second terminal busbar installed in the front busbar frame of FIG. 3; and FIG. 9 is a plan view schematically illustrating the inner busbar and the wire portion installed in the rear busbar frame of FIG. 2.

[0073] Referring to FIGS. 5 through 9, an inner busbar (130), a first terminal busbar (140), and a second terminal busbar (150) are installed on the front busbar frame (110F). An inner busbar (130) is installed on the rear busbar frame (110R), but the first terminal busbar and the second terminal busbar are not installed. A plurality of inner busbars (130), a first terminal busbar (140), and a second terminal busbar (150) installed on the front busbar frame (110F) are connected in series with a plurality of inner busbars (130) installed on the rear busbar frame (110R). Accordingly, battery cells embedded in the battery module (100) are connected in series.

[0074] A plurality of substrate joints (163) are formed on the circuit board (160). The circuit board (160) is installed on the front and rear busbar frames (110F, 110R), respectively. A flexible substrate (FPCB) may be used as the circuit board (160). The number of substrate joints (163) is equal to the total number of the inner busbar (130), the first terminal busbar (140), and the second terminal busbar (150). The plurality of substrate joints (163) may be arranged in a row along the longitudinal direction of the circuit board (160).

[0075] The bonding member (180) is connected to the second terminal busbar (150), and the wire portion (170) is soldered. The area of ​​the bonding member (180) is formed to be significantly larger than the diameter of the wire portion (170). The bonding member (180) may be formed in a plate shape. Even if a soldering defect occurs when the wire portion (170) is soldered to the substrate bonding portion (163) of the circuit board (160) and the bonding member (180), the wire portion (170) can be re-soldered to the unsoldered portion of the bonding member (180).

[0076] Soldering joins the base material by using soldering paste without melting the base material or by melting it locally. Additionally, since the wire portion (170) has a small diameter, the soldering area can be significantly reduced when soldered to the base material. Accordingly, during the soldering process, a tension clamp (not shown) can pull the wire portion (170) to test the bonding strength of the soldering portion. Furthermore, non-destructive testing can be performed without cutting the soldering portion, and the soldering portion can be fully monitored in real time during the soldering process.

[0077] In contrast, welding heats and melts homogeneous or dissimilar base materials using highly concentrated thermal energy or high temperatures. During this process, the weld area is bonded by rearranging the atomic bonds of the different base materials and may undergo different chemical or thermal deformations. Laser welding, ultrasonic welding, and resistance welding can be applied to such welding processes. Furthermore, welding significantly increases the weld area (weld bead) compared to soldering.

[0078] A plurality of wire sections (170) are each soldered to the corresponding first electrode lead (121), the corresponding substrate joint (163), and the joint member (180). The diameter of the wire section (170) has a cross-sectional area that is significantly smaller than that of the substrate joint (163). When the above-mentioned wire section (170) is soldered to the first electrode lead (121) and the substrate joint (163), the area of ​​the soldered section occupies a significantly smaller area than the unsoldered portion of the first electrode lead (121) and the substrate joint (163). Accordingly, if a soldering defect occurs on one side of the wire section (170), the one side of the wire section (170) can be resoldered to the unsoldered portion of the first electrode lead (121) and the substrate joint (163).

[0079] In addition, since the multiple wire portions (170) are soldered to the first electrode lead (121), the substrate joint portion (163) of the circuit board (160), and the joint member (180) using soldering paste without melting, it is not necessary to install a separate sensing plate to weld the circuit board (160) to the inner bus bar (130) or the first electrode lead (121). Accordingly, the welding process of connecting the sensing plate to the circuit board (160) can be omitted. In addition, since the sensing plate does not need to be used, the number of parts can be reduced and the assembly time of the battery module (100) can be shortened.

[0080] In addition, even when a flexible circuit board (160) is used, it is not necessary to perform a clamping operation to fix the position of the flexible circuit board (160) and the sensing plate using a clamping device. Since the clamping operation performed directly by the operator can be omitted, the soldering process of the circuit board (160) and the wire portion (170) can be automated.

[0081] Additionally, the wire portion (170) is soldered at a significantly lower temperature compared to laser welding. Accordingly, since almost no chemical or thermal deformation occurs when the first electrode lead (121), the substrate joint portion (163) of the circuit board (160), and the bonding member (180) are soldered, the wire portion (170) can be soldered again to the first electrode lead (121), the substrate joint portion (163) of the circuit board (160), and the bonding member (180).

[0082] Additionally, since the wire portion (170) is soldered to the first electrode lead (121), the substrate joint portion (163) of the circuit board (160), and the bonding member (180) by soldering paste, the first electrode lead (121), the substrate joint portion (163) of the circuit board (160), and the bonding member (180) may not melt at all or may melt only locally and slightly.

[0083] Additionally, after soldering the wire portion (170), a tension clamp can pull the wire portion (170) to test the bonding strength of the soldered portion. Accordingly, the bonding strength of the soldered portion can be evaluated through non-destructive testing. Furthermore, since the bonding strength evaluation of the wire portion (170) can be performed together with the soldering process of the wire portion (170), the time required for the strength evaluation of the soldered portion can be significantly reduced. Additionally, if a soldering defect occurs in the wire portion (170), the wire portion (170) can be quickly resoldered.

[0084] The wire section (170) includes a wire body section (171), a first wire joint section (172), and a second wire joint section (173).

[0085] The wire body portion (171) can be formed in a shape that bends toward the substrate joint portion (163) and the inner busbar (130). At this time, the wire body portion (171) can be formed to be inclined toward both sides with respect to the center.

[0086] The first wire joint (172) is formed curved on one side of the wire body (171) and can be soldered to the substrate joint (163).

[0087] The second wire joint (173) is formed curved on the other side of the wire body (171) and can be soldered to the first electrode lead (121) or the joint member (180).

[0088] Since the wire body portion (171) is formed in a bent shape and the first wire joint portion (172) and the second wire joint portion (173) are formed in a curved shape, the wire portion (170) can be easily soldered in response to the height difference even if a height difference (H: see FIG. 7) occurs between the substrate joint portion (163), the inner bus bar (130), and the joint member (180).

[0089] Additionally, the first wire joint (172) may be formed convexly toward the substrate joint (163). Accordingly, even if the height of the wire body (171) changes, the first wire joint (172) can stably contact the substrate joint (163), and the contact area of ​​the first wire joint (172) can be prevented from changing.

[0090] The second wire joint (173) may be formed convexly toward the first electrode lead (121) or the joining member (180). For example, the first wire joint (172) and the second wire joint (173) may be formed roundly. Even if the height or angle of inclination of the wire body (171) is different, the second wire joint (173) can stably contact the first electrode lead (121) or the joining member (180), and the contact area and soldering area of ​​the second wire joint (173) can be prevented from changing.

[0091] Meanwhile, the battery module (100) described above forms an interconnected board (ICB) by connecting battery cells in series via a plurality of inner busbars (130), a first terminal busbar (140), and a second terminal busbar (150). To connect the battery cells in series, a first electrode lead (121) and a second electrode lead (122) of different polarities are connected to the inner busbar (130). Additionally, only the first electrode lead (121) is connected to the first terminal busbar (140), and only the second electrode lead (122) of opposite polarity to the first electrode lead (121) is connected to the second terminal busbar (150).

[0092] The substrate joint (163) may be formed of a material of the same type as either the first electrode lead (121) or the second electrode lead (122). For example, the substrate joint (163) may be formed of an aluminum material of the same type as the first electrode lead (121). Since the substrate joint (163) and the first electrode lead (121) are formed of the same type of material, sufficient soldering strength of the wire portion (170) can be secured. Here, the term "same type of material" basically includes all materials that are identical in alloy composition and alloy ratio, or different within a certain range.

[0093] The first electrode lead (121) may be formed of the same material as the wire portion (170). Since the first electrode lead (121) and the wire portion (170) are formed of the same material, sufficient bonding strength can be secured when soldering the first electrode lead (121) and the wire portion (170). In addition, since the first electrode lead (121) and the second electrode lead (122) are connected together to the inner busbar (130), the wire portion (170) and the first electrode lead (121) can be soldered to the inner busbar (130).

[0094] The second electrode lead (122) may be formed of the same material as the inner busbar (130). Accordingly, the second electrode lead (122) and the inner busbar (130) may be welded by welding such as a laser.

[0095] The joining member (180) may be formed of the same material as the wire portion (170). For example, the joining member (180) and the wire portion (170) may include aluminum. Accordingly, sufficient joining strength can be secured between the joining member (180) and the wire portion (170).

[0096] In contrast, since the interconnect board connects battery cells in series, the first terminal busbar (140) is connected to the first electrode lead (121) of the same material as the wire section (170), but the second terminal busbar (150) is connected to the second electrode lead (122) of a different material as the wire section (170). Since the second electrode lead (122) is formed of a material different from that of the wire section (170), it may be difficult to secure sufficient bonding strength during soldering. Accordingly, in the present invention, a bonding member (180) of the same material as the wire section (170) is connected to the second terminal busbar (150), and the wire section (170) is soldered to the bonding member (180) to increase the bonding strength of the wire section (170).

[0097] Meanwhile, the inner busbar (130), the first electrode lead (121), and the second electrode lead (122) can be joined by melting them with a laser. Accordingly, even if the inner busbar (130), the first electrode lead (121), and the second electrode lead (122) are formed of different materials, sufficient joining strength can be secured.

[0098] The above-mentioned joining member (180) can be laminated onto the second terminal busbar (150) and joined by melting it onto the second terminal busbar (150) by a laser. Although the joining member (180) and the second terminal busbar (150) are made of different materials, sufficient joining strength can be secured by laser welding.

[0099] Additionally, the joining member (180) may be formed in a plate shape. The joining member (180) may be formed in the shape of a square plate that is slightly narrower than the width of the second electrode lead (122). Accordingly, since the second electrode lead (122) and the wire portion (170) are made of different materials, they can be welded by a laser or the like, and since the wire portion (170) and the joining member (180) are made of the same material, they can be soldered. Accordingly, sufficient soldering strength of the wire portion (170) can be secured.

[0100] Next, a battery module according to a second embodiment of the present invention will be described. Since the second embodiment is substantially identical to the first embodiment described above, except for the shape of the second terminal busbar and the connecting member, the same reference numerals will be assigned to identical components, and their descriptions will be omitted.

[0101] FIG. 10 is a schematic perspective view illustrating an inner busbar, a first terminal busbar, a second terminal busbar, and a wire section installed in a front busbar frame of a battery module according to a second embodiment of the present invention; FIG. 11 is an exploded perspective view schematically illustrating an inner busbar, a first terminal busbar, a second terminal busbar, and a wire section installed in a front busbar frame of FIG. 10; FIG. 12 is an enlarged view schematically illustrating a state in which the wire section is soldered to the first electrode lead of the inner busbar and the circuit board in a front busbar frame of FIG. 10; FIG. 13 is an enlarged view schematically illustrating a state in which the wire section is soldered to the joining member of the second terminal busbar and the circuit board in a front busbar frame of FIG. 10; and FIG. 14 is a plan view schematically illustrating an inner busbar, a first terminal busbar, and a second terminal busbar installed in a front busbar frame of FIG. 10.

[0102] Referring to FIGS. 10 to 14, the second terminal busbar (150) of the battery module (100) according to the second embodiment of the present invention includes an extension portion (152) extending from the side of the second terminal busbar (150), and a joining member (181) is joined to the extension portion (152).

[0103] The extension part (152) is formed of the same material as the second terminal busbar (150). Additionally, the extension part (152) can be integrally formed with the second terminal busbar (150) when manufacturing the second terminal busbar (150). Alternatively, the second terminal busbar (150) and the extension part (152) may be manufactured separately and then welded together by laser welding or the like.

[0104] The bonding member (181) and the extension member (152) can be bonded by melting them with a laser. At this time, the extension member (152) may be formed of the same material as the second terminal bus bar (150), and the bonding member (181) may be formed of the same material as the wire member (170). Accordingly, the extension member (152) and the bonding member (181), which are of different materials, can be bonded by laser welding, and the wire member (170) and the bonding member (181), which are of the same material, can be bonded by soldering. Furthermore, since the sensing plate is not connected to the circuit board (160), the circuit board (160) and the sensing plate do not need to be clamped, so the wire member (170) and the bonding member (181) can be soldered by an automated process.

[0105] The joining member (181) may be formed in a plate shape. At this time, the joining member (181) may be formed to be the same size as or slightly smaller than the extension part (152).

[0106] Since the components installed on the rear busbar frame in the second embodiment are substantially identical to the components installed on the rear busbar frame of the first embodiment, the illustration has been omitted.

[0107] Next, a battery module according to a third embodiment of the present invention will be described. Since the third embodiment is substantially identical to the first embodiment described above, except for the shape of the second terminal busbar and the connecting member, the same reference numerals will be assigned to identical components, and their descriptions will be omitted.

[0108] FIG. 15 is a schematic perspective view illustrating an inner busbar, a first terminal busbar, a second terminal busbar, and a wire portion installed on a front busbar frame of a battery module according to a third embodiment of the present invention; FIG. 16 is an exploded perspective view schematically illustrating an inner busbar, a first terminal busbar, a second terminal busbar, and a wire portion installed on a front busbar frame of FIG. 15; FIG. 17 is an enlarged view schematically illustrating a state in which the wire portion is soldered to the first electrode lead of the inner busbar and the circuit board in the front busbar frame of FIG. 15; FIG. 18 is an enlarged view schematically illustrating a state in which the wire portion is soldered to the joining member of the second terminal busbar and the circuit board in the front busbar frame of FIG. 15; FIG. 19 is a perspective view schematically illustrating the structure of the second terminal busbar and the joining member in the front busbar frame of FIG. 15; and FIG. 20 is FIG. 15 FIG. 21 is a schematic plan view illustrating an inner busbar, a first terminal busbar, and a second terminal busbar installed on a front busbar frame, and FIG. 21 is a schematic perspective view illustrating the state in which the second terminal busbar and the joining member are friction stir welded in the front busbar frame of FIG. 15.

[0109] Referring to FIGS. 15 to 21, in a battery module (100) according to a third embodiment of the present invention, a joining member (182) is formed of the same material as the wire portion (170) and can be welded to the side of a second terminal bus bar (150). The joining member (182) may be an aluminum pad or an aluminum bar, and the wire portion (170) may be an aluminum wire. Additionally, the second terminal bus bar (150) may be made of copper.

[0110] The joining member (182) and the second terminal busbar (150) can be welded by friction stir welding. A friction stir welding tool (T) has a threaded projection (probe) formed on its lower surface. When the friction stir welding tool (T) is rotated at high speed and the projection is inserted into the workpiece (150, 182), frictional heat is generated by friction between the friction stir welding tool (T) and the workpiece (150, 182). This frictional heat softens the area around the friction stir welding tool (T), and the softened part is forcibly mixed by plastic flow, thereby welding.

[0111] Of course, the above-mentioned joining member (182) and the second terminal busbar (150) can be welded by laser welding.

[0112] In the third embodiment, the components installed on the rear busbar frame are substantially identical to the components installed on the rear busbar frame of the first embodiment, so the illustration has been omitted.

[0113] Although the present invention has been described above with reference to the illustrated drawings, the present invention is not limited by the embodiments and drawings disclosed in this specification, and it is obvious that various modifications can be made by a person skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration according to the present invention were not explicitly described while describing the embodiments of the present invention above, it is natural to acknowledge that the effects predictable by said configuration should also be recognized. Explanation of the symbols

[0114] 10: Battery pack 11: Case 100: Battery module 101: Module Frame 103F,103R: End plates 110F,100R: Busbar frame 111: Inner Rib 112: Outer Rib 113: Slit section 114: Section Rib 115: Through-hole section 116: Settling Rib 117: Fixing pin 121: First electrode lead 122: Second electrode lead 130: Inner Busbar 140: Terminal 1 Bus Bar 141: First bend 150: Terminal 2 Bus Bar 151: Second bend 152: Extension part 160: Circuit board 161: Fixed hole part 163: Substrate junction 170: Wire section 171: Wire body 172: First wire joint 173: Second wire joint 180,181,182: Joining members T: Friction stir welding tool

Claims

Claim 1 A battery module comprising: a plurality of inner busbars disposed on a busbar frame, each having a first electrode lead and a second electrode lead connected thereto; a first terminal busbar disposed on the busbar frame and having a first electrode lead connected thereto; a second terminal busbar disposed on the busbar frame and having a second electrode lead having opposite polarity to the first electrode lead connected thereto; a circuit board having a plurality of substrate joints formed thereon; a plurality of wire portions soldered to the first electrode lead and the substrate joints; and a joining member joined to the second terminal busbar and having the wire portions soldered thereto. Claim 2 A battery module according to claim 1, wherein the joining member is formed of the same material as the wire part. Claim 3 A battery module according to paragraph 2, wherein the joining member and the wire portion comprise aluminum. Claim 4 A battery module according to paragraph 2, wherein the bonding member and the wire portion are bonded by melting soldering paste. Claim 5 In paragraph 2, the battery module, wherein the first electrode lead is formed of the same material as the wire part. Claim 6 A battery module according to claim 1, wherein the inner busbar, the first electrode lead, and the second electrode lead are joined by melting by a laser. Claim 7 A battery module according to claim 1, wherein the second electrode lead is formed of the same material as the inner busbar. Claim 8 A battery module according to claim 1, wherein the first terminal busbar and the second terminal busbar are disposed on the outer edge of a plurality of inner busbars. Claim 9 A battery module according to claim 1, wherein the bonding member is laminated to the second terminal busbar and bonded to the second terminal busbar by melting by a laser. Claim 10 In claim 1, the battery module, wherein the joining member is formed in a plate shape. Claim 11 A battery module according to claim 1, wherein the second terminal busbar includes an extension extending from the side of the second terminal busbar, and the joining member is joined to the extension. Claim 12 In claim 11, the battery module, wherein the extension is formed of the same material as the second terminal busbar. Claim 13 A battery module according to claim 11, wherein the bonding member and the extension are bonded by melting by a laser. Claim 14 In claim 11, the above-mentioned joining member is formed in a plate shape, a battery module. Claim 15 A battery module according to claim 1, wherein the joining member is formed of the same material as the wire part and welded to the side of the second terminal busbar. Claim 16 A battery module according to claim 15, wherein the joint member and the second terminal busbar are welded by friction stir welding. Claim 17 In item 15, the above-mentioned joining member is a battery module formed in a plate shape. Claim 18 A battery module according to claim 1, wherein the wire portion comprises: a wire body portion that is bent toward the substrate joint portion and the inner busbar; a first wire joint portion formed curvedly on one side of the wire body portion and soldered to the substrate joint portion; and a second wire joint portion formed curvedly on the other side of the wire body portion and soldered to the first electrode lead or the joint member. Claim 19 A battery module according to claim 18, wherein the first wire joint is formed convexly toward the substrate joint and the second wire joint is formed convexly toward the first electrode lead or the joint member. Claim 20 A battery module according to claim 19, wherein the first wire joint and the second wire joint are formed in a rounded shape.

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